Comparative genomic analysis identifies potential adaptive variation in Mycoplasma ovipneumoniae.

Mycoplasma ovipneumoniae is associated with respiratory disease in wild and domestic Caprinae globally, with wide variation in disease outcomes within and between host species. To gain insight into phylogenetic structure and mechanisms of pathogenicity for this bacterial species, we compared M. ovipneumoniae genomes for 99 samples from 6 countries (Australia, Bosnia and Herzegovina, Brazil, China, France and USA) and 4 host species (domestic sheep, domestic goats, bighorn sheep and caribou). Core genome sequences of M. ovipneumoniae assemblies from domestic sheep and goats fell into two well-supported phylogenetic clades that are divergent enough to be considered different bacterial species, consistent with each of these two clades having an evolutionary origin in separate host species. Genome assemblies from bighorn sheep and caribou also fell within these two clades, indicating multiple spillover events, most commonly from domestic sheep. Pangenome analysis indicated a high percentage (91.4 %) of accessory genes (i.e. genes found only in a subset of assemblies) compared to core genes (i.e. genes found in all assemblies), potentially indicating a propensity for this pathogen to adapt to within-host conditions. In addition, many genes related to carbon metabolism, which is a virulence factor for Mycoplasmas, showed evidence for homologous recombination, a potential signature of adaptation. The presence or absence of annotated genes was very similar between sheep and goat clades, with only two annotated genes significantly clade-associated. However, three M. ovipneumoniae genome assemblies from asymptomatic caribou in Alaska formed a highly divergent subclade within the sheep clade that lacked 23 annotated genes compared to other assemblies, and many of these genes had functions related to carbon metabolism. Overall, our results suggest that adaptation of M. ovipneumoniae has involved evolution of carbon metabolism pathways and virulence mechanisms related to those pathways. The genes involved in these pathways, along with other genes identified as potentially involved in virulence in this study, are potential targets for future investigation into a possible genomic basis for the high variation observed in disease outcomes within and between wild and domestic host species.

Suspected True Hermaphroditism in a Free-ranging Gray Wolf (Canis lupus) in Interior Alaska, USA.

Hermaphroditism or intersexuality occurs endogenously in most mammal species. We document the behavior and physical and anatomic appearance of a suspected true hermaphroditic free-ranging wild gray wolf (Canis lupus) in Denali National Park and Preserve, Alaska, USA.

Highly Pathogenic Avian Influenza A(H5N1) Virus Clade 2.3.4.4b Infections in Wild Terrestrial Mammals, United States, 2022.

We describe the pathology of natural infection with highly pathogenic avian influenza A(H5N1) virus of Eurasian lineage Goose/Guangdong clade 2.3.4.4b in 67 wild terrestrial mammals throughout the United States during April 1‒July 21, 2022. Affected mammals include 50 red foxes (Vulpes vulpes), 6 striped skunks (Mephitis mephitis), 4 raccoons (Procyon lotor), 2 bobcats (Lynx rufus), 2 Virginia opossums (Didelphis virginiana), 1 coyote (Canis latrans), 1 fisher (Pekania pennanti), and 1 gray fox (Urocyon cinereoargenteus). Infected mammals showed primarily neurologic signs. Necrotizing meningoencephalitis, interstitial pneumonia, and myocardial necrosis were the most common lesions; however, species variations in lesion distribution were observed. Genotype analysis of sequences from 48 animals indicates that these cases represent spillover infections from wild birds.

Multilocus Sequence Typing of Mycoplasma ovipneumoniae Detected in Dall's Sheep (Ovis dalli dalli) and Caribou (Rangifer tarandus grantii) in Alaska, USA.

In 2018, Mycoplasma ovipneumoniae was detected in free-ranging caribou (Rangifer tarandus grantii) and Dall's sheep (Ovis dalli dalli) in Alaska, US. Evaluation of additional nasal swabs and archived tissues for M. ovipneumoniae suggested that this bacterium was widespread geographically and temporally in populations of both species. Multilocus sequence typing of four loci identified a single, novel, apparently stable strain type of M. ovipneumoniae in 11 Dall's sheep and 15 caribou in multiple populations across Alaska sampled over a period of 15 yr (2004-19). This strain type differs from those detected to date from wild or domestic sheep (Ovis aries) or goats (Capra aegagrus hircus) tested in Alaska or the lower 48 states. Although the population health implications of this strain are unknown, it has not been associated with population-wide mortality events. The presence of this strain does not decrease the potential risk from the introduction of a pathogenic M. ovipneumoniae strain associated with severe disease in other wildlife populations; therefore, continued monitoring for signs of disease and additional strains is important.

LABORATORY CONCORDANCE STUDY FOR THE MOLECULAR DETECTION OF MYCOPLASMA OVIPNEUMONIAE.

As part of a respiratory pathogen survey of Alaska wildlife, we conducted a concordance study to assess Mycoplasma ovipneumoniae detection among three different PCR assays using a total of 346 nasal swabs sampled from four species (Dall's sheep, Ovis dalli dalli; mountain goats, Oreamnos americanus; caribou, Rangifer tarandus granti; and moose, Alces alces gigas), and two taxonomic subfamilies (Bovidae subfamily Caprinae and Cervidae subfamily Capreolinae). A federal research laboratory performed two PCR assays (LM40 and intergenic spacer region [IGS]), and a state diagnostic laboratory performed the third (universal Mycoplasma [UM]). Overall concordance was good, ranging from 93% to 99%, which was probably a result of low detection rate of M. ovipneumoniae. Due to differences in positive agreement, the quality of concordance between LM40 and both IGS and UM was considered fair. However, the quality of concordance between IGS and UM was excellent. All three PCR methods detected M. ovipneumoniae in a non-Caprinae species (caribou), and the LM40-PCR assay also detected M. ovipneumoniae in additional Caprinae species. The LM40-PCR assay detected M. ovipneumoniae in a larger number of samples than did the other two assays (IGS, UM). Because of potential differences in detection rates, it is critical to consider test parameters when evaluating a host population for the presence of M. ovipneumoniae.

Draft Genome Sequence of a Novel Mycoplasma Species Identified from the Respiratory Tract of an Alaska Moose (Alces alces gigas).

The mycoplasmas represent a large and diverse group of bacteria, many of which are pathogens of humans and animals. Here, we describe a draft genome sequence of a novel Mycoplasma species. This novel Mycoplasma species has potential to cause false-positive PCR results for Mycoplasma ovipneumoniae, a respiratory-associated pathogen of ruminants.

The biogeography of the caribou lungworm, Varestrongylus eleguneniensis (Nematoda: Protostrongylidae) across northern North America.

Varestrongylus eleguneniensis (Nematoda; Protostrongylidae) is a recently described species of lungworm that infects caribou (Rangifer tarandus), muskoxen (Ovibos moschatus) and moose (Alces americanus) across northern North America. Herein we explore the geographic distribution of V. eleguneniensis through geographically extensive sampling and discuss the biogeography of this multi-host parasite. We analyzed fecal samples of three caribou subspecies (n = 1485), two muskox subspecies (n = 159), and two moose subspecies (n = 264) from across northern North America. Protostrongylid dorsal-spined larvae (DSL) were found in 23.8%, 73.6%, and 4.2% of these ungulates, respectively. A portion of recovered DSL were identified by genetic analyses of the ITS-2 region of the nuclear rDNA or the cytochrome oxidase c subunit I (COI) region of the mtDNA. We found V. eleguneniensis widely distributed among caribou and muskox populations across most of their geographic prange in North America but it was rare in moose. Parelaphostrongylus andersoni was present in caribou and moose and we provide new geographic records for this species. This study provides a substantial expansion of the knowledge defining the current distribution and biogeography of protostrongylid nematodes in northern ungulates. Insights about the host and geographic range of V. eleguneniensis can serve as a geographically extensive baseline for monitoring current distribution and in anticipating future biogeographic scenarios under a regime of accelerating climate and anthropogenic perturbation.

Organochlorine contaminant concentrations in blubber of young Steller sea lion (Eumetopias jubatus) are influenced by region, age, sex, and lipid stores.

Contaminant exposure is particularly important for species and populations of conservation concern, such as the Steller sea lion (Eumetopias jubatus). We used blubber samples (n = 120) to determine organochlorine concentrations, including polychlorinated biphenyls (PCBs) and dichloro-diphenyl-trichloroethane (DDTs), and blood samples (n = 107) to estimate total body lipids based on the hydrogen isotope dilution method. We assessed the influence of age, sex, condition, and geographic area on contaminant concentrations in blubber and contaminant body load. The concentration of ΣPCBs was highest in pups (<6 months) from the Aleutian Islands, and the concentrations in males were higher than females in all regions. The ΣPCBs and ΣDDTs concentrations and loads decreased with increasing mass in pups, however, there were no regional or sex differences in contaminant load. Within each of the five age classes, the concentrations of ΣPCBs and ΣDDTs decreased with increasing mass, but overall these OCs increased with age. Further, accounting for the lipid content, a potential proxy for energy balance, in the animal load reduced or removed the regional and sex effects present in age models for contaminants. We propose, that adjusting OCs concentration by the lipid content of the blubber sample alone may not fully account for the variability in OC concentrations associated with differences in condition or energy states between young Steller sea lions.

Mycoplasma ovipneumoniae Associated with Polymicrobial Pneumonia in a Free-Ranging Yearling Barren Ground Caribou (Rangifer tarandus granti) from Alaska, USA.

Mycoplasma ovipneumoniae has been reported in association with respiratory disease in the wild only in members of the subfamily Caprinae of the family Bovidae. We identified M. ovipneumoniae in a cervid: a free-ranging barren ground caribou (Rangifer tarandus granti) yearling with polymicrobial bronchopneumonia.

Mycoplasma ovipneumoniae in Wildlife Species beyond Subfamily Caprinae.

Elucidating the emergence of Mycoplasma ovipneumoniae-associated respiratory disease in ruminants requires identification of the pathogen host range. This bacterium was thought to be host restricted to subfamily Caprinae, but we describe its identification in healthy moose, caribou, and mule deer and diseased mule and white-tailed deer, all species in subfamily Capreolinae.

Oil fouling in three subsistence-harvested ringed (Phoca hispida) and spotted seals (Phoca largha) from the Bering Strait region, Alaska: Polycyclic aromatic hydrocarbon bile and tissue levels and pathological findings.

Oil spills of unknown origin were detected in three oil-fouled, ice-associated seals from the Alaska Bering Strait region collected by Alaska Native subsistence hunters during fall 2012. Bile analyses of two oiled seals indicated exposure to fluorescent polycyclic aromatic hydrocarbon (PAH) metabolites but levels of some metabolites were similar to or lower than biliary levels in harvested unoiled ice seals. Oiled seals had elevated tissue PAH concentrations compared to tissue levels of PAHs determined in unoiled ice seals. However, regardless of oiling status, tissue PAH levels were relatively low (<50 ng/g, wet weight) likely due to rapid PAH metabolism and elimination demonstrated previously by vertebrates. Hepatic, pulmonary, and cardiac lesions were observed in oiled seals in conjunction with measurable PAHs in their tissue and bile. This is the first study to report tissue and bile PAH concentrations and pathologic findings of oiled ice seals from the U.S. Arctic.

Butorphanol-Azaperone-Medetomidine for the Immobilization of Captive Caribou ( Rangifer tarandus granti) in Alaska, USA.

A combination of butorphanol-azaperone-medetomidine was used to immobilize four captive caribou ( Rangifer tarandus granti) in Palmer, Alaska, US. The average induction time for this combination was 5:17±2:06 min. Inductions were smooth, and recoveries were excellent. This drug combination may provide an alternative to the use of potent opioids for immobilizing caribou.

First isolation of Brucella pinnipedialis and detection of Brucella antibodies from bearded seals Erignathus barbatus.

Brucella species infecting marine mammals was first reported in 1994 and in the years since has been documented in various species of pinnipeds and cetaceans. While these reports have included species that inhabit Arctic waters, the few available studies on bearded seals Erignathus barbatus have failed to detect Brucella infection to date. We report the first isolation of Brucella pinnipedialis from a bearded seal. The isolate was recovered from the mesenteric lymph node of a bearded seal that stranded in Scotland and typed as ST24, a sequence type associated typically with pinnipeds. Furthermore, serological studies of free-ranging bearded seals in their native waters detected antibodies to Brucella in seals from the Chukchi Sea (1990-2011; 19%) and Svalbard (1995-2007; 8%), whereas no antibodies were detected in bearded seals from the Bering Sea or Bering Strait or from captive bearded seals.

Hyperparasitism and Non-Nidicolous Mating by Male Ixodes angustus Ticks (Acari: Ixodidae).

Ixodes angustus (Neumann) (Acari: Ixodidae) is considered to be a nidicolous tick in that the entire life cycle can be completed in the host nest. Males of this tick have been reported to be rare on hosts because most mating occurs in the host nest and males typically do not feed on hosts. Collections of I. angustus in Alaska departed slightly from this paradigm in that nine males were collected from hosts, mostly in copulation with females that were attached to mammalian hosts. Non-nidicolous mating was therefore more common in I. angustus collected in this study than has been reported previously. A hyperparasitic male I. angustus was found firmly attached via its hypostome and chelicerae to the ventral idiosoma of a partially engorged female I. angustus that was attached to, and feeding on, an American red squirrel, Tamiasciurus hudsonicus (Erxleben). This hyperparasitic interaction is discussed and illustrated with a Scanning Electron Micrograph.

DISEASE COMPLEXITY IN A DECLINING ALASKAN MUSKOX (OVIBOS MOSCHATUS) POPULATION.

The muskox ( Ovibos moschatus ) population inhabiting the eastern North Slope (ENS) of Alaska, US declined dramatically during 1999-2006, whereas populations in western Alaska (WA) were stable or increasing. To understand morbidity and mortality factors contributing to the decline, Alaska Department of Fish and Game conducted pathologic investigations of carcasses from 2005 until 2008. Additionally, archived sera from both ENS and WA muskoxen collected during 1984-92, before the documented beginning of the ENS decline; sera collected during 2000, near the beginning of the decline; and contemporary sera (from live capture-release, adult females) collected during 2006, 2007, and 2008 were analyzed to determine whether prevalence of antibody to potential pathogens differed in the two areas or changed over time. The pathogens investigated were those that were believed could cause lameness or poor reproduction or adversely affect general health. Furthermore, trace mineral levels, hemograms, and gastrointestinal parasites were evaluated in live adult females captured 2006-08. Pathologic investigations identified several comorbid conditions, including predation, polyarthritis caused by or consistent with Chlamydophila spp. infection, hoof lesions, copper deficiency, contagious ecthyma, verminous pneumonia, hepatic lipidosis suggestive of negative energy balance, and bacterial bronchopneumonia due to Trueperella pyogenes and Bibersteinia trehalosi . Pathogens suspected to be newly introduced in the ENS muskox population on the basis of serologic detection include bovine viral diarrhea, respiratory syncytial virus, Chlamydophila spp., Brucella spp., Coxiella burnetii , and Leptospira spp., whereas parainfluenza virus-3 antibody prevalence has increased in the WA population. Although multiple disease syndromes were identified that contributed to mortality and, in combination, likely limited the ENS muskox population, further holistic investigations of disease agents, trace mineral status, and nutritional factors in conjunction with intensive demographic and environmental analyses would provide a better understanding of factors that influence Alaskan muskox populations.

New Records of Ticks (Acari: Ixodidae) From Dogs, Cats, Humans, and Some Wild Vertebrates in Alaska: Invasion Potential.

During 2010-2016, tick specimens were solicited from veterinarians, biologists, and members of the public in Alaska. Eight species of ticks were recorded from domestic dogs. Some ticks were collected from dogs with recent travel histories to other countries or other U.S. states, which appears to explain records of ticks not native to Alaska such as Amblyomma americanum (L.) (lone star tick), Ixodes scapularis (Say) (blacklegged tick), and Ixodes ricinus (L.). However, we recorded Dermacentor variabilis (Say) (American dog tick) from dogs (and humans) both with and without travel history, suggesting that this nonindigenous tick could be establishing populations in Alaska. Other ticks commonly recorded from dogs included the indigenous Ixodes angustus Neumann and the invasive Rhipicephalus sanguineus (Latreille) (brown dog tick). Domestic cats were only parasitized by one tick species, the native I. angustus Six species of ticks were recorded from humans: A. americanum (with and without travel history), Dermacentor andersoni Stiles (Rocky Mountain wood tick; travel associated), D. variabilis (with and without travel history), Haemaphysalis leporispalustris (Packard) (rabbit tick, native to Alaska), I. angustus, and R. sanguineus. Ixodes angustus predominated among tick collections from native mammals. Also, Ixodes texanus Banks (first record from Alaska) was collected from an American marten, Martes americana (Turton), H. leporispalustris was recorded from a snowshoe hare, Lepus americanus Erxleben, and Ixodes auritulus Neumann was collected from a Northwestern crow, Corvus caurinus Baird. The establishment of D. variabilis, D. andersoni, A. americanum, and/or I. scapularis in Alaska would have strong implications for animal and human health.

THIAFENTANIL-AZAPERONE-XYLAZINE AND CARFENTANIL-XYLAZINE IMMOBILIZATIONS OF FREE-RANGING CARIBOU (RANGIFER TARANDUS GRANTI) IN ALASKA, USA.

Carfentanil-xylazine (CX) has been the primary drug combination used for immobilizing free-ranging ungulates in Alaska, US since 1986. We investigated the efficacy of a potential new drug of choice, thiafentanil (Investigational New Animal Drug A-3080). Captive trials indicated that thiafentanil-azaperone-medetomidine could provide good levels of immobilization. However, field trials conducted in October 2013 on free-ranging caribou ( Rangifer tarandus granti) calves showed the combination too potent, causing three respiratory arrests and one mortality. The protocol was revised to thiafentanil-azaperone-xylazine (TAX), with good results. The induction time was not significantly different between the two combinations. However, the recovery time was significantly shorter for the TAX group than for the CX group. A physiologic evaluation was performed on 12 animals immobilized on CX and 15 animals on TAX. Arterial blood was collected after induction and again after 10 min of intranasal oxygen supplements (1 L/min). Both groups had significant increases in partial pressure of arterial oxygen after oxygen treatment. There was a concurrent significant increase in partial pressure of arterial carbon dioxide in both groups. Rectal temperature increased significantly in both groups during the downtime, which is consistent with other studies of potent opioids in ungulates. On the basis of our results, we found TAX to be a potential alternative for the current CX protocol for immobilizing free-ranging caribou calves via helicopter darting.

Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska.

The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy.

Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus).

Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to be Toxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from <1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ13C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host.

Restricted evaluation of Trichodectes canis (Phthiraptera: Trichodectidae) detection methods in Alaska gray wolves.

Trichodectes canis (Phthiraptera: Trichodectidae) was first documented on Alaska (USA) gray wolves (Canis lupus) on the Kenai Peninsula in 1981. In subsequent years, numerous wolves exhibited visually apparent, moderate to severe infestations. Currently, the Alaska Department of Fish and Game utilizes visual inspection, histopathology, and potassium hydroxide (KOH) hide digestion for T. canis detection. Our objective was to determine optimal sampling locations for T. canis detection. Wolf hides were subjected to lice enumeration using KOH hide digestion. Thirty nine of the 120 wolves examined had lice. Of these 39, total louse burdens ranged from 14 to an extrapolated 80,000. The hides of 12 infested animals were divided into 10 cm by 10 cm subsections and the lice enumerated on a subsection from each of four regions: neck; shoulder; groin; and rump. Combining the data from these 12 wolves, the highest mean proportions of the total louse burdens on individual wolves were found on the rump and differed significantly from the lowest mean proportion on the neck. However, examination of the four subsections failed to detect all infested wolves. Hides from 16 of the 39 infested animals were cut into left and right sides, and each side then cut into four, approximately equal sections: neck and shoulder; chest; abdomen; and rump. Half hides were totally digested from 11 wolves, and whole hides from 5. For these 21 half hides, the highest mean proportions of total louse burdens were found on the rump, and this section had the highest sensitivity for louse detection, regardless of burden. However, removal of this large section from a hide would likely be opposed by hunters and trappers.